Refraction is the degree of nearsightedness or farsightedness, and refraction is usually indicated by the letter “S”. Refraction, also known as optometry, is a very important test in ophthalmology, through which the patient can determine what kind of refractive state he or she is in. The most common method of refraction is computerized optometry. There are some data on the computerized optometry sheet, including the specific degrees of spherical lens, astigmatism, and axial position. The refractive spherical lens is the number of degrees that indicates hyperopia or myopia. Hyperopia is usually preceded by “+” and myopia is usually preceded by “-“, and if it is zero, it means that there is no myopia or hyperopia. When the optometry results are abnormal, you need to choose a suitable way to correct your vision under the guidance of your doctor.